424 Lang. — Studies in the Development and 
which consist of two to seven sporangia. These sori are 
difficult to detect in the mature cone, but sometimes the 
direction of the long axes of the crowded sporangia and 
of their lines of dehiscence, which run radially in the more 
regular sori, enable their limits to be determined. As serial 
sections in a plane parallel to the surface of the sporophyll 
show, the stalks of the sporangia composing a sorus converge 
as the surface of the sporophyll is approached. In the 
intervals between the sori hairs are present, while they are 
not found between the individual sporangia of a sorus. Each 
sporophyll bears a large number of sporangia 1 ; these are less 
numerous on the scales near the apex of the cone, but their 
arrangement is the same. 
The youngest cones that could be obtained without risk 
of injury to the plant were too far advanced to enable any 
observations on the development of the sporophylls to be 
made ; they measured 28 mm. in length, exclusive of the 
peduncle. The early stages of development of the sori and 
sporangia could, however, be followed in cones of this size, for 
not only were the sporophylls in the apical region in a less 
advanced stage of development than those inserted nearer 
the base, but sori of different ages were present on the 
same sporophyll. 
The young sporophyll (Fig. 1) has a short stalk. The 
horizontal soriferous portion is distinguishable by its white 
glistening appearance from the hairy surface of the terminal 
scale-like part, which extends as a V-shaped projection 
between the two lobes of which the horizontal portion con- 
sists, but does not completely separate them. The sori in 
the youngest scales examined formed a slightly curved row 
on each side, immediately within which was a group of sori 
differing in size from one another. The outer row of sori gives 
rise to the two outer rows of sporangia, while the inner group 
consists of the first developed sori of more central sporangia. 
These are seen to be distinct from one another in older scales 
1 According to Al. Braun more than ioo ^Die Frage nach der Gymnospermie 
der Cycadeen : Monatsber. d. K. Akad. d. Wiss., Berlin, 1875, p. 343, note). 
